The compiler (HP aCC) says:

> /opt/aCC/bin/cc -Ae -b -L/usr/local/lib/hpux32 build/temp.hp-ux-B.11.31-ia64-3.8-pydebug/var/osipovmi/cpython/Modules/_ctypes/_ctypes.o build/temp.hp-ux-B.11.31-ia64-3.8-pydebug/var/osipovmi/cpython/Modules/_ctypes/callbacks.o build/temp.hp-ux-B.11.31-ia64-3.8-pydebug/var/osipovmi/cpython/Modules/_ctypes/callproc.o build/temp.hp-ux-B.11.31-ia64-3.8-pydebug/var/osipovmi/cpython/Modules/_ctypes/stgdict.o build/temp.hp-ux-B.11.31-ia64-3.8-pydebug/var/osipovmi/cpython/Modules/_ctypes/cfield.o -L/usr/local/lib/hpux64 -L/usr/lib/hpux32 -L/usr/lib/hpux64 -L/usr/lib -L/lib -L/usr/local/lib/hpux32 -L/usr/local/lib -lffi -ldl -o build/lib.hp-ux-B.11.31-ia64-3.8-pydebug/_ctypes.so -fPIC
> cc: warning 901: unknown option: `-fPIC': use +help for online documentation.

On clang or GCC this is a compile time option, never a link option. For HP aCC objects must be compiled with +z -- which actually happens -- and linked with +b to a shared library -- which also happens here --. One can safely drop this switch from setup.py.